1. Technical Field
The present disclosure relates to a lead wire and a pacemaker using the lead wire.
2. Discussion of Related Art
In generally, pacemakers are electronic therapeutic devices which can be implanted into human bodies. The pacemakers can emit pulse currents to stimulate tissues of organs which are not healthy to treat illnesses of the organs.
Lead wires are important elements in the pacemakers. The lead wires can provide pulse signals to the organs, and sense intrinsic activities of the organs for a purpose of suppressing pulse signals whenever a natural activity occurred within a predetermined time period after the last natural activity or a pulse signal. Thus the lead wires serve as both stimulating electrodes to provide pulse signals and sensing electrodes to electrically sense the intrinsic activities of organs.
The requirements for an optimum stimulating electrode and an optimum sensing electrode are sometimes conflicting. For example, the optimum stimulating electrode should have a very small surface area exposed to the heart tissue in order to achieve a low pacing threshold and a high current density. The sensing electrode requires a large surface area exposed to the heart tissue in order to detect a relatively low level electrical signal indicating natural heartbeat activities. However, the lead wires have a same working surface to function as the sensing electrode and the stimulating electrode, which may not meet the requirements of the sensing electrode and the stimulating electrode at the same time. Thus, the pulse signals and the sensing signals may not be accurate and reliable, making the pacemakers using lead wires inaccurate and unreliable.
What is needed, therefore, is to provide a lead wire and a pacemaker using the same, which can overcome the shortcomings as discussed above.